Apparatus for making metal tubing



F.- MAGIDSONI Feb. 3, 1925. 1,525,081

-APPARATUS FOR MAKING METAL TUBING Original Filed Oct. 27 920 6 Sheets-Sheet l WITNESSES 11A M/l/E/VTOR k 11am. I Y 1% v.1 I: 1 @115,

I Feb; '1 925.

1,525,081 F. MAGIDSON APPARATUS FOR MAKING METAL TUBING Original Filed Oct. 27 1920 6 Sheets-sheaf. 2

Fll3-Z..

. I/Vl/EA/TOR WITNESSES a y alium i 29 gwg Feb. 3, 1925; 1,525,081:

F. MAGIDSON v APPARATUS FOR MAKING METAL TUBING Original Filed Oct, 27 1920 6 Sheets-Sheet 5 I 1,525,081 F. -MAG|DSON APPARATUS FOR MAKING-METAL TUBING Original Filed 001;. 2 1920 e Sheets-Sheet 4 Feb. 3

. A f Q A Q FM. fa H x o w \M M h 6% m6 y 0H QR vb mwg Fm \M R 2 L i W a Om. {Ill 1. 0Q QR @m N v RN Q5 7 Q g I mlw w A m v Q. :AEMQ Hm M V F. MAGIDISON APPARATUS FOR MAKING METAL TUBING Original Filed Oct; 27, 1920 6 Sheets-Sheet 5 INVENTOR F. MAGIDSON APPARATUS FOR MAKING METAL TUBING Feb. 3, 1925..

Original Filed oat. 27 1920 6 Sheets-Sheet 6 WITNESSES (NYE/V701? Patented Feb. 3, 1925.

ilNlThQ TATES PATENT QFFICE.

FRANK MAGIDSON, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOE TO PROGRESS TUBE COMPANY, A CORPORATION OF FENNSYLVANIA.

APPARATUS FOR MAKING METAL TUBING.

Application filed October 27, 1920, Serial No. 419,847.

To all 207mmit may concern:

Be it known that I, FRANK MAoIDsoN, a citizen of the United States, and a resident of Pittsburgh, in the county of Allegheny and State of Pennsylvania, have made a new and useful Improvement in Apparatus for Making Metal Tubing, of which the following is a specification.

This invention relates to apparatus for making metal tubing and more especially to apparatus for making butted tubing or other hollow sections of any desired shape or cross-section from skelp or strip metal while in a cold state.

A further object is to provide apparatus whereby metal tubing of relatively light gage maybe made at small cost.

A still further object is to provide apparatus whereby skelp or strip metal in a single pass or operation may be converted into butted tubing of any desired cross section.

A still further object is to provide apparatus automatic in its operation and by means of which reeled strip material may be fed and continuously converted into butted tubing of any desired shape and of the some as the metal strip.

These, as well as other objects which will readily appear to those skilled in the metal tubing art, I attain by means of the apparatus described in the specification and illustrated in the drawings accompanying and forming part of this application and throughout which similar elements are denoted by like characters.

The apparatus broadly consists of means for forcibly propelling a flat strip of metal longitudinally into and through forming dies whereby it is transversely bent into tube form; in means for preventing buckling or distortion of the strip from the propolling means to the forming dies; and means for swaging the strip during its longitudinal movement and transverse bending into finished form.

In the drawings. Figure 1 is'a top plan view of apparatus embodying this invention. Fig. 2 is a view of the front or entering end of the apparatus. Fig. 3 is a sectional view taken on line 3 3 of Fig. 1. Fig. i is a sectional view taken on line 4-4 of Fig. 1, looking in the direction of the arrows. Fig. 5 is a detail view of a portion of the apparatus. Fig. 6 is an enlarged enewed. December 29, 1924.

fragmentary view of portions of the appa ratus. Figs. 7 8 and 9 are enlarged detail views of portions of the apparatus. Fig. 10 is a top plan view illustrating the progressive transverse bending of the strip around the mandrel. Figs. 11, 12, 13 and l i are cross sectional views of the dies or swedges used for progressively bending the strip transversely into tube form and Figs. 15, 16 and 17 are cross sections of dies and mandrels used in making tubing of various sections. These views illustrate the tubing within the closed portion of the die.

In describing my invention by aid of the views abovereferred to, I desire to point out that the same are merely illustrative of the apparatus as actually built and that I do not care to confine my invention to the precise construction and arrangement of parts shown. The following description is therefore to be broadly construed as including suit-able constructions and arrangement of parts which are obviously equivalent to those hereinafter referred to.

Strip propelliny' and i/iding mechanism.

Cylindrical rolls 20 and 21 journaled in suitable bearings 22 and 23 mounted in end frames 24 and 25 as is now common in mill construction, are employed for propelling the strip material. Roll 21 is mounted in rigid bearing, while roll 20 is vertically adjustable to accommodate different thicknesses of skelp or strip material. The pres sure on the strip exerted by the rolls is secured by means of adjusting screws 26, and rolls 20 and 21 are geared together by gears 27 and 28, so that both are driving rolls. As the skelp or strip material used does not vary much in thickness from the thinnest to the thickest gage, gears are chosen which will allow sufficient separation of the rolls to accommodate varying thicknesses of material. Roll 21 is driven from a suitable motor 29 through a train of gears 30. 31 and 32 and a worm 33 and wormwheel 34: secured to the roll shaft.

A feed table 35 is provided at the entrance side of the rolls along which the skelp or strip material is guided to the rolls and for guiding the strip to the center of the rolls, guides 36 adjustable laterally of the table are provided. These are mounted on a cross rod 37 and locked in adjustable positions thereon by set-.screws38,

The rolls 20 and 21 are each provided with a centrally located rectangular groove, the groove 01. roll 20 being numbered 39 and that of roll 21. 40. These grooves must be materially less in width than any strip that is to be used. as it is necessary to have the strip contact with sufficient roll surface on each side of. the groove so that it may be forced through the dies.

Located on the leaving side of the feed rolls are two guides for the strip; one guide 41 is located below the strip while one located above the strip. Each of these guides is provided with an extension 4-2. which extends into the groove of its roll to a point in front of meeting line of the rolls. Guide tl is rigid and its upper surtace is tangent to roll 21. Guide 42 is vertically adjustable and is locked in adjusted position by means of a locking" screw at which extends through a slot 4-5 in a support frame 46. Guide 4-12 is made adjustable to accommodate different thicknesses of strip material and will be raised and lowered with roll 20, so that its lower face is always tangent to roll 20. Guides 41 and 42 prevent the strip from buckling and cause it to travel in a straight line to the die.

Forming and steer inn mocha/12218772..

The strip is torced through a forming die and around a mandrel located in the die and is swaged or pressed into finisher term during its travel through the die.

The die is sectional and is made up of two parts 4-7 and 48 of identical shape, and this will be so whenever tubing of symmetrical section is to be made. Vihen the die sections are in contact one with the other, they provide a through passage 49 of the same cross-section as the cross-section of the finished tube. The forward or entering face of the composite die is diagonally disposed with relation to the line of movement of the strip passing between guides 41 and 4-2 and therefore diagonally to the major axis of passage 49.

Cutting away the entrance face of the die diagonally to the line of travel of the strip presents a forming channel which increases in depth as it approaches the rear portion of the die or in other words, the

walls of the die channel increase in height from the forward end of the die to that point at which the walls meet to form the closed die passage. By means of these walls of progressively increasing height the metal strip as itis forced through the die, is simultaneously bent laterally or transversely in opposite directions with relation to its median line and this bending occurs in increments until the opposite edges of the strip arrive in proximity one to the other at the top of the die passage.

If the tubing or other hollow article to be "formed is of symmetrical contour the channels in the die sections will be made so that the strip will be transversely bent equally on opposite sides of its median line, so that the median line of the strip the major axis of the tube and the tube seam will lie in one and the same plane.

A mandrel 51 having a forwardly ext nding support portion 52 above the open end of the die passage. extends into the closed portion of the die passage and this portion in cross section is the same as the interior or here of the finished tube.

Each die section is provided with a tenon 53 which fits within a hole formed for its receptionin a cross head or slide The die sections are clamped in place by means of clamp screw. each threaded through an arm 56 ot a bracket 57 bolted to its crosshead. lhe cross-heads are arranged to slide toward and from one another with in guide ways 58 formed in a supporting member bolted at 60 to the end members of the apparatus.

Each of the cross-heads in its under portion is provided with a slot or channel 61 within which the upper bifurcated arm oi. one oi. a pair of operating levers is adapted to be reciprocated. These levers are pivotally mounted at 64 to the support member 59 and each lever is provided with a long arm 65 carrying' an anti-friction roller 66 at its lower end.

A cam wheel 67 provided with tooth-like portions 68 and hollows 6% is carried on a shaft 70 which lies between. rollers 66. Shaft 70 at its forward end carries a pinion 71 which meshes with gear 31. Each of the cross-heads is connected up to theupper arm of one of the operating levers and this connecting means consists of a rod 72 which xtends through a hole 73 in the outer end of the cross-head and lies between the tin-cute parts ot the upper arm of its lover. The inner end of the rod is provided with an enlarged head 74 which abuts against the inner side of the lever.

Two bufier devices, one carried by each of the rods 72 abut against the outer ends of the cross heads. Each buffer device coinprises a rubber butter element 75 which surrounds its rod 72. Each butter element 7 is confined between end plates 76 and 77. Each butter assembly is secured together by means of bolts 78. The bolts also form means for initially con'ipressing the buffer elements 75; rods 72 are threaded to receive nuts 79 and lock nuts 80.

The'tooth portions 68 of cam wheel 67, as the wheel rotates. cause the die sections to move into contact one with the other. and the hollows 69 between the tooth sections allow the die sections to be forced apart or the die opened, by the strip of Hill metal as it is :forced between the sections. T he buffer elements of the two rods 72 must be adjusted so that the cross heads will travel simultaneously and in the same amount to insure uniform swaging action of both die sections as to speed and intensity of blow. The buffers offer some resistance in case foreign matter enters the die.

A guide 81, bolted to support member 59, and axially alined with relation to the die passage 49 serves as a guide and support for the tubing as it issues from the die.

In a machine adjusted so as to feed skelp or strip metal at the rate of ten (10) feet )er minute through the die I have found that satisfactory results are obtained by reciprocating the die sections together 750 times per minute, or, in other words, closing the die 750 times per minute.

It will he understood that the cam wheel for reciprocating the die sections can be driven independently of the rolls and by a separate motor, so that the periodicity of the swaging operations may be varied to suit the particular material being worked on.

It will be seen that by progressively bending strip material laterally or transversely with relation to its median line and forming the same in a sectional vibrating swaging die, tubing of any desired cross-section may be produced by a single operation or single pass.

As the strip is fed continuously, any suitable means may be used for welding the seam of the tube as it issues from guide member 81 and any suitable means may be used for cutting the tubing to length. If it is made from skelp, the pieces leaving the rolls may be pushed through the die by the next piece entering the rolls as the guides ail and 42 will prevent the skelp from buckling.

In accordance with the provisions of the Patent Statutes, I have described the prin ciple of operation of my invention, together with one form of apparatus, but I desire to have it understood that the device shown is only illustrative and that the invention can be carried out in other Ways.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is 1. In apparatus for forming tubing, a mandrel, means for longitudinally propelling strip material past said mandrel, dies mounted for reciprocation on opposite sides of said mandrel, and means for re ciprocating said dies While the strip material is moving, whereby said material while forwardly moving is transversely bent on opposite sides of its median line around said mandrel and subjected to periodically applied pressuresulficient to sWage-finish the same.

2. In apparatus for forming tubing, .a mandrel, rolls for propelling strip material longitudinally and past sald mandrel, a

longitudinally split die, the halves of which are mounted for reciprocation on opposite sides of said mandrel, means for guiding the strip material from said rolls to said die, and means for reciprocating the sections of said die while the strip material is moving whereby the same, While moving, is transversely bent on opposite sides of its median line around said mandrel.

3. In apparatus for forming tubing, a mandrel, a transversely divided combined forn'iing and swaging die, mounted for oo-operative reciprocation toward and from said n'iandre'l, means for reciprocating the sections of said die at frequentintervals, means for guiding strip material to the entrance of said die and for preventing same from buckling and rolls for forcing strip material through said die during its reciprocations.

4-. In apparatus for forming tubing from skelp or other strip metal, means for longitudinally moving the material, and periodically reciprocating means for bending the material transversely on opposite sides of its median line and simultaneously with such bending for subjecting the bending material to periodically applied transverse pressure sutlicient to swage the same to finished form.

5. In apparatus for forming butted tubing, guides for compelling strip material passing therebetween to move in a straight line, feed rolls grooved so as to straddle said guides and propel strip material therebetween, a mandrel and means surrounding said mandrel for bending strip material transversely in opposite directions around said mandrel, and means for subjecting that portion of the strip adjacent the mandrel to periodically applied transverse pressure during its longitudinal movement.

6. In apparatus for making tubing from strip metal, a die provided with a through passage and having its entrance opening located in a die face diagonally disposed to the major axis of said passage, a mandrel supported adjacent the entrance of said die. and extending into said passage, rolls for propelling flat metal strip through said die, and means for preventing the strip from buckling during its passage from said rolls to said die.

7. In a machine for making tubing from strip metal, a longitudinally split die, a mandrel supported adjacent the entrance of said die and extending thereinto, means for feeding strip material into and through said die, and means operating in conjunction with said material to periodically reciprocate the portions of said die during the passage of material therethrough.

8. In apparatus for forming hollow sections, a longitudinally split die formed for progressively bending material to finished form, a mandrel extending into said die from its entrance side, rolls for forcing strip material through said die, guides located above and below the strip material and extending from a plane including the axes of said rolls to said die for preventing the strip from buckling, and means for reciprocating the sections of said die towards said mandrel.

9. In apparatus for forming hollow sections, a longitudinally split die, a mandrel supported in front of said die and extending thereinto, means for reciprocating the sections of said die towards said mandrel rolls for feeding strip material past said mandrel and through said die, guides extending from said die into grooves in said rolls and past the plane including the axes of said rolls for preventing strip material forced by said rolls through said dies from buckling between said rolls and said die.

10. In apparatus for forming hollow sections, strip feeding rolls provided with alined circumferential. grooves, swage dies for receiving and acting on strip material propelled by said rolls, and guides extending from said die into said grooves past the plane including the axes of said rolls.

In testimony whereof, I have hereunto subscribed in name this 25th da of October, 1920.

FRANK MAGIDSON. 

